#region LICENSE

// The contents of this file are subject to the Common Public Attribution
// License Version 1.0. (the "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of the License at
// https://github.com/NiclasOlofsson/MiNET/blob/master/LICENSE. 
// The License is based on the Mozilla Public License Version 1.1, but Sections 14 
// and 15 have been added to cover use of software over a computer network and 
// provide for limited attribution for the Original Developer. In addition, Exhibit A has 
// been modified to be consistent with Exhibit B.
// 
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
// the specific language governing rights and limitations under the License.
// 
// The Original Code is MiNET.
// 
// The Original Developer is the Initial Developer.  The Initial Developer of
// the Original Code is Niclas Olofsson.
// 
// All portions of the code written by Niclas Olofsson are Copyright (c) 2014-2018 Niclas Olofsson. 
// All Rights Reserved.

#endregion

using System;
using System.Threading;
using MiNET.Entities;

namespace MiNET.Worlds
{
	public class EntityManager
	{
		public const long EntityIdUndefined = -1;
		public const long EntityIdSelf = 2;

		private long _entityId = EntityIdSelf + 1;

		public long AddEntity(Entity entity)
		{
			if (entity.EntityId == EntityIdUndefined)
			{
				entity.EntityId = Interlocked.Increment(ref _entityId);
			}

			return entity.EntityId;
		}

		public void RemoveEntity(Entity caller, Entity entity)
		{
			if (entity == caller) throw new Exception("Tried to REMOVE entity for self");
			if (entity.EntityId != EntityIdUndefined) entity.EntityId = EntityIdUndefined;
		}
	}
}